PYRIMIDOPYRIMIDINES, PYRIMIDOPYRIMIDOAZEPINES, AND AN IMIDAZOTRIAZINE BY THREE COMPONENT REACTION

Article abstract of DOI:10.3987/COM-92-S(T)102

Recent examples of the three component reaction: iminophosphoranes / isocyanates / heteroarenes (imines) are described.The uracil (1) affords with O-methyl-ε-caprolactim ether and isocyanates the pyrimido<4',5':4,5>pyrimido<6,1-a>azepines (6a-c) and with benzylideneaniline (8) the pyrimido<4,5-d>pyrimidines (9a-d), while azodicarboxylate gives the isofervenuline, pyrimido<4,5-e><1,2,4>triazine (11).Furthermore, pyrimido<4,5-d>pyrimidine (15) is obtained via 14 from 1, N-phenylbenzimidoyl chloride (13), and phenylisocyanate, while the tautomeric mixture 17A <=> 17B results from treatment of 6-aminouracil (16) with 13; interception with dimethyl acetylenedicarboxylate gives the pyrido<2,3-d>pyrimidine (19).